There are important medical applications that would benefit from a system which detected and located part per billion metal levels in an individual cell, with a low-power affordable package. This would assist in the research of Alzheimer's and Parkinson's diseases, prostate cancer and the investigation of trace level environmental contamination. A microanalysis technique using monochromatic x-rays is proposed for measuring ppb concentrations of metal species in standard samples. Similar techniques that have only been practical with costly synchrotrons are possible with lower power, cost effective systems using a new, revolutionary doubly-curved crystal optic. Monochromatic microprobe x- ray fluorescence (MMXRF), with this new crystal focusing optic, uses the monochromatic beam to achieve significantly lower background levels and is capable of detecting ppb levels of metal in biological samples. This Phase I project will experimentally demonstrate ppb detection of Cr, Mn, Fe, and Cd in standard samples using a Cu K beam, and will determine the detection limits. The feasibility of the MMXRF technique for mapping of Mn and Fe in brain tissue and for measuring Cd in prostate tissue will be evaluated and a Phase II proposal will be submitted to construct an optimized system to provide experimental data using brain tissue and other human samples. PROPOSED COMMERCIAL APPLICATIONS: Commercial applications will be seen in analytical laboratories and medical research centers in their investigation of the effects of toxic metals and other trace elements on biological functions, the thin film and semi-conductor industries who are interested in the sub-ppm contamination of heavy metals, forensics, and any other industries where the detection ability to locate sub ppm concentrations of heavy elements is desired.